very common problem with many amps. The MFJ antenna analyzer works to get the same job done. the better pass threw tune helps your incoming receive . I use a variable cap. tune it and put cap on my LCR meter and read it than put a fixed cap in. 73's
This is awesome BBI! Tuning seems to be the meat and potatoes of having a working amp or not working. I always look forward to hearing you say the biggest mud duck in Idaho thing at the end of your vids.
Hay Luke I am s 30 plus year electronics tech and just want to say thank you fro doing what you do. I am also a ham operator that got my humble beginnings in citizen band radio, my call is KN4RBJ I live in South Carolina please keep up the great work you do in the radio community
If your claim is that adding this part lowers the SWR as seen by the antenna system during receive, you'll have to reverse the connections to the analyzer to measure that, since (a tiny amount of) power is flowing from the antenna toward the radio. This is assuming that the radio actually presents a 50 ohm load to the antenna - very few do. As shown, this will only help transmit operation when the amp is in line, but not keyed.
I have actual question. How could I calculate out that capacitance if I actually wanted to or how would I know if it was instead a capacitance issue and I needed more inductor... like a by the book please and thank you of course. I so look forward to your latest offerings I only wish I could be of more value to the human race. Sorry high school electronics teacher just put on movies and disappeared. (Alcoholic) Thank you. Mr E
Can you use a MFJ-269 antenna analyzer hooked to the input of a Ameritron AL-811H to the output into a dummy load and tune each input circuit bands on the back of the amplifier? Or am I doing this all wrong. I can't seem to find a video of this procedure. Not yet at least. I know I'm a dummy, but I'm trying. Thanks
@wickeddreams911 yes Sir I did. And tuned each band slug one at a time. Also putting the band selector switch in each band and adjusted the slug to the lowest SWR. All of them tuned down into the low teens. That's the lowest each one would tune. I don't know why it will not tune any lower. Unless it's because the amplifier is unplugged, with cover off, and the tubes out. It needed dusting out. With the relay unkeyed, I get a 1.1 SWR on all bands. I'm using a plastic tool to adjust each slug also. I'm probably not doing something correctly.
Outstanding. Every time I watch these videos I learn. THAT's why I'm a Patreon member Thanks Mr. BBI
very common problem with many amps. The MFJ antenna analyzer works to get the same job done. the better pass threw tune helps your incoming receive . I use a variable cap. tune it and put cap on my LCR meter and read it than put a fixed cap in. 73's
Great instructional video Mr. BBI, thanks again.
This is awesome BBI! Tuning seems to be the meat and potatoes of having a working amp or not working.
I always look forward to hearing you say the biggest mud duck in Idaho thing at the end of your vids.
Could you add a video on how to tune the transmt SWR for all bands on the SB-220
Hay Luke
I am s 30 plus year electronics tech and just want to say thank you fro doing what you do.
I am also a ham operator that got my humble beginnings in citizen band radio, my call is KN4RBJ I live in South Carolina
please keep up the great work you do in the radio community
Hi Luke,
Very useful information. Can a NanoVNA be used just like the KC901S to check the pass through? You and the family stay safe. 73 WJ3U
Yes it's nowhere near as accurate the graphics are much lower there's a 35% variance between unit at least in the three that I've tested, but yes...
Sad, I'm looking at purchasing one.
If your claim is that adding this part lowers the SWR as seen by the antenna system during receive, you'll have to reverse the connections to the analyzer to measure that, since (a tiny amount of) power is flowing from the antenna toward the radio. This is assuming that the radio actually presents a 50 ohm load to the antenna - very few do. As shown, this will only help transmit operation when the amp is in line, but not keyed.
BBI you sir your the book of knowlege.
Love it
Hi Mr. BBi, I thought it was called Pass Thru Tune or Pass Thru SWR.. ♠W.G.
Mr BBI, you know how to "crush the competition" with these simple fixes. What do you recommend for the SB-201? Thx a bunch.
I'm recommended what way?? Are you inquiring about how to do the 11 meter mod
Brother you stated 40 puff ceramic obviously, but what's the voltage? I may have to replace my network analyzer. Flying blind. Thank you. TexasDon
500 volt
I have actual question.
How could I calculate out that capacitance if I actually wanted to or how would I know if it was instead a capacitance issue and I needed more inductor...
like a by the book please and thank you of course.
I so look forward to your latest offerings I only wish I could be of more value to the human race.
Sorry high school electronics teacher just put on movies and disappeared. (Alcoholic)
Thank you. Mr E
When you built a brand new SB-220 you used 2x 25pf. Will it make any difference? Thank You.
Nah
I think your tip needs tinning brother man!
I want to learn how to tune an amp!
Can you use a MFJ-269 antenna analyzer hooked to the input of a Ameritron AL-811H to the output into a dummy load and tune each input circuit bands on the back of the amplifier? Or am I doing this all wrong. I can't seem to find a video of this procedure. Not yet at least. I know I'm a dummy, but I'm trying. Thanks
Did you close the relay so you're actually using the tuning circuit?
@wickeddreams911 yes Sir I did. And tuned each band slug one at a time. Also putting the band selector switch in each band and adjusted the slug to the lowest SWR. All of them tuned down into the low teens. That's the lowest each one would tune. I don't know why it will not tune any lower. Unless it's because the amplifier is unplugged, with cover off, and the tubes out. It needed dusting out. With the relay unkeyed, I get a 1.1 SWR on all bands. I'm using a plastic tool to adjust each slug also. I'm probably not doing something correctly.
I bought spare 572B tubes also. So I was going to take out the 811A tubes and replace them with 4 of the 572B tubes as well.
Well crap I didn't tune the plate and load at all. So I'll try that now and see if the SWR drops down. I'm a big dummy.
47pf mylar..what voltage? I take it that 600v would be okay
500v
@@BoxBuilderIdaho Thanks bro..
Great tip BBI, thanks! And bonus, everyone is being civil & polite too. :) 73 Tod KJ6H